A storage system including a plurality of SAS expanders (hereinafter, referred to as expander) has been known. In this kind of storage system, a storage device is coupled to the expanders, and a command from an initiator device to the storage device passes through the expanders.
This kind of storage system is disclosed, for example, in PTL1. According to PTL1, initiator devices are coupled to both ends of a plurality of expanders coupled in series (for example, see FIG. 10).